Conventional wind machines are used primarily to prevent springtime frost damage to crops. These conventional wind machines can also introduce water into their wind stream to prevent heat and sun damage to crops in the late summer and early fall.
Prior wind machine devices with liquid dispersion features include U.S. Pat. No. 1,993,635, which disperses water through the hub of the wind machine's propeller to prevent frosting and sunburning. Water is carried up the tower of the wind machine within a stationary water pipe, which is connected to the propeller hub. Additionally, a perforated pipe, filled with a dust material, circles the tower. The perforated pipe delivers the dust material to the lower edge of the rotating propeller for dispersal into the wind stream.
Another liquid dispersing wind machine is found in U.S. Pat. No. 2,238,120, which discloses a spraying device having a manifold attached to the propeller's guard. The guard is circular and the nozzles are positioned on the manifold across the face of the rotating propeller.
U.S. Pat. No. 3,067,541 shows an air circulating apparatus in which water or other treatment fluid, is disbursed by a pair of rotor blades. The blades receive the fluid through a conduit where it is disbursed through discharge orifices on the blades. The blades are mounted on an axis of rotation that is substantially perpendicular to the ground surface. The blades are then turned in a plane that is horizontal to the ground surface.
U.S. Pat. No. 3,296,739 also discloses a rotating orchard heater. A liquid, such as water or fuel is supplied to nozzles mounted on a circular fan guard. A manifold is positioned along the circumference of the fan guard to deliver the liquid to the nozzles at the circumference of the fan guard.
It is desirable, however, to introduce fluids into the wind machine's airstream downstream of the propeller blades. Nozzles mounted on the fan guard, proximate the outer surface of the propeller, can only serve when the propellers draw the air stream past the wind machine and push the air stream, past the nozzles and away from the wind machine. If the flow is reversed, the fluid from the nozzles would be sucked into the propeller, rather than away from it. The fluid, injected from the nozzles mounted to the outer fan guard, coats the propeller and the wind machine. This reverse flow alternative is undesirable. Even if the fluid is only water, it can quickly damage the wind machine, invading the bearings and gears. Additionally, the wind machine's efficiency is reduced because significant amounts of the fluid are lost by coating the propeller and the wind machine, or at least deflected away from the intended target. If the wind machine is operating in freezing conditions, the atomized fluid drawn through the propeller can freeze on the propeller, creating a hazard that can quickly result in damage to the wind machine, and potential injury to persons or objects near the wind machine. Therefore, the fluid must be injected into the airstream at the pressurized, downstream side of the propeller, rather than the upstream, suction side and preferably well clear from potential contact with the wind machine.
U.S. Pat. No. 3,944,139 addressed this problem by disclosing a wind machine having a nozzle-bearing circular manifold that rings around the tower and is mounted just below a rotatable fan. A cam attached to the fan's housing sequentially activates valves on the nozzles as the housing rotates. The fluid stream substantially avoids the wind machine and is injected into the pressurized side of the propeller. However, as shown in FIG. 1 therein, the injected moisture fails to reach the upper portions of the pressurized air stream.
U.S. Pat. No. 5,082,177, by the inventor of the present invention also discloses a ring-shaped manifold for distributing a fluid to nozzles positioned about a wind machine tower. The nozzles are positioned in an array circumferentially about the tower, below the wind machine. The array of nozzles injects the fluid into the wind stream from vertical risers mounted on the tower ringing manifold The risers follow along the tower and are attached to the tower at regular intervals. This array of nozzles injects the fluid to the lower half of the rotor, or propeller of the wind machine.
U.S. Pat. No. 5,222,665, also by the inventor of the present invention, includes a circumferential array of nozzles connected to a manifold that rings the tower proximate the wind machine. The '665 apparatus better distributes the fluid to the entire wind stream as compared with prior devices. However, there are portions of the wind stream, especially in the region directly above the wind machine, which receive less of the injected fluid. A wind machine fluid injection system is needed that more evenly disperses the fluid to the entire generated wind stream.